Treatment of hydrocarbon oils



Patented may i8, 1937 "PATENT OFFICE mamn'r or mnociumon OILS Jacque C.Morrell, Chicago, 111., assignor to Universal 011 Products Company,Chicago, Ill... a corporation of Delaware No Drawing.

4 Claims.

This application is a' continuationrin-part of v my application SerialNo. 581,022, filed December 14, 1931.

This invention relates to the treatment of hy- 5 drocarbon oils andrefers more particularly to .the treatment of the lighter distillatesproduced in the cracking of heavier oils although similar distillatesproducedfrom the primary or noncracking distillation of crude petroleumsmay also be treated.

More specifically the invention relates to the treatment of suchhydrocarbon mixtures while in a heated vaporous condition, a processbeing disclosed which accomplishes the necessary refining of such vaporsprior to their condensation and-substantially eliminates the necessityfor extensive treatment of the distillates and their subsequentrerunning, thus eifeoting much needed economies.

It has been recognized for some time by those engaged in the petroleumindustry that the usual method of treating cracked distillates withsulphuric acid followed by neutralization and rerunning to produce endpoint gasoline possesses numerous inherent disadvantages due principallyto the need for special auxiliary treating equipment and the necessityfor rerunning the treated distillates. Even though distillates ofgasoline end point are treated, rerunning is usually necessary onaccount of the formation of high boiling polymers, sulphuric acidderivatives, sulfow compounds, etc. which raise theflnal boiling pointof the gasoline. or the proposed vapor phase treating methods thus fartried a I few have attained commercial statusynotably treatments withsolid adsorbents such as fullers earth. As yet, however, it cannot be'said that any one type of vapor phase treatment has been found which iseflicient enough to completely 40 supersede the customary acid treatingand rerunning of cracked distillates. The present invention provides animprovement over existing commercial processes which possesses markedadvantages over those now in vogue, the details 5 of the presentinvention being set forth in the following paragraphs.

In one specific embodiment the invention comprises the treatment ofhydrocarbon vapors, particularly cracked hydrocarbon oil vapors, with 50liquid sulphuric acid solutions of various concentration containingsubstantially neutral organic compounds or the reaction products betweenthese compounds and sulphuric acid.

It will be evident from the preceding para- 55 graph expressing thepreferred embodiment of Application July 23, 1934, Serial No. 736,556

the invention that it comprises essentially a modification of the ideaof using dilute aqueous sulphuric acid, the range of use of the latterbeing very limited due to the fact that'under the conditions oftemperature and pressure common to 5 fractionatorswhich are handlingcracked vapors that any dilute aqueous sulphuric acid which may be addedthereto is rapidly concentrated to a strength which isundesirablebecause of its powerful oxidizing and charring effect, producl0 ing thuscokey sludges and too severe an efiect upon the vapors. The use ofspacing agents of the types mentioned in the preceding paragraph enablesthe use of sulphuric acid in-a sufliciently diluted condition foreflicient vapor phase treat- 15 ments since the vapor pressure ofsuchvcompounds, properly selected with regard to their physical andchemicalproperties, may be conproper chemical vand physicalcharacteristics. 30 i The invention further contemplates-the use ofsulfonic acids of the chlor, nitro and hydroxyl derivatives of thearomatic or ring hydrocarbons mentioned. For example, diluting orspacing reagents may be made by sulfonating monochlorbenzol,mononitrobenzol, or phenol. Poly-substituted compounds and mixedsubstitution compounds may also be employed as bases for the manufactureof sulfonlc acids. For example,

metadlchlor benzol may be sulfonated, or para-' 40 dinitrobenzol orresorcinol may be used. Compounds similar to cresols and other phenolsof homologs of benzol may also be used as starting materials when theirsulionic acids have the right properties. Suitable compounds for use asdiluent or spacing agents may be formed by reacting upon unsaturatedchain compounds with sulfuric acid, the product of these reactions beingcompounds of the type of mono or dialkyl sulfates. The particularolefins available for the manufacture of such compounds will in generalbe those which do not suffer extensive polymerization such as themouooleflns corresponding to the normal parafllns.

Another class of compounds which may be uti- 66 lized and which may or.may not undergo su'lfonation during their use are the aldehydes andketones, of ring compounds such as, for example, benzaldehyde, diphenylketone, et cetera.

From the -=statements Just made concerning the types of compounds whichmay be employed as diluting or spacing materials it will be evident thata large number of reagent treating solutions of varying. composition"may be made up to suit the needs of different treatments. While in mostcases the virtue of the treatingsolution employed is due principally tothe sulfuric acid, it is recognized that the organic compounds used ass'pacing agents may at times exert a definite chemical influence uponthe reactions other than merely moderating the effect of the sulfuricacid. It will. also be evident that the selection of any particularcompound or mixture of compounds for use withthe sulphuric acid will bedetermined by solubility relations,

the extent of refining treatment necessary upon the vapors, the generaloperating conditions and the matter of economy in the cost of thereagents. However, such problems will be solved by those familiar withthe treating art without great dimculty.

The process may be conducted in any type of apparatus suitable forefficiently contacting vapors with liquid treating reagents. A filledtower containing crushed rock, fragments of porcelain, Raschig rings ormetallic filler is readily utilizable, the scheme of operation in such acase being to pass the vapors upwardly through the tower countercurrentto the descending treating solutionwhich has been introduced above thebaiiling material through distributing means to assist in securingintimate contact of oil vapors and liquid. At other times greateradvantage may be gained by passing the vapors downwardly along with thetreating solution, this serving in some instances to allow betterseparation and disposition of sludge and heavy reaction products.Treatments of high efilciency may be obtained by utilizing towers of thespaced-tray type, the trays being perforated or supporting bubble capssuch as are commonly employedin fractionating towers in the oilindustry. Towers may be lined with lead or other materials to minimizecorrosion effects or suitably chosen corrosion resisting metals may beemployed in their construction.

Another type of operation which maybe successfully employed involves thesimple expedient of merely allowing the vapors to rise through a pool oftreating solution, the solution being circulated to insure thoroughmixing and used until substantially spent, at which time the vaporsundergoing treatment may be diverted to a fresh supply of reagent inparallel connected towers, thus insuring substantially continuousoperation.

Owing to the possibility of varying the composition of the treatingsolutions over a wide range, the process is adaptable for use underpractically all conditions of temperature and pressure encountered incracking, primary distilling or rerunning operations upon vaporscontaining large amounts of gasoline boiling range fractions. Thetemperatures prevailing in such distillations are usually includedwithin the range of 200 to 600 F. and pressures from atmospheric orslightly superatmospheric to high superatmospherlc such as for examplepressures in the neighborhood of 300 pounds per square inch or higher.

Treatments may be employed alone or in combination with other types ofvapor phase treatment. For example, the vapors may be treated withammonia or alkali solutions to neutralize and remove hydrogen sulfide,after which the process of the invention is applied and vapors after thetreatment may be further neutralized, subjected to filtering orsedimentation to remove entrained particles or further neutralized andfiltered to remove substantially all acidic reaction products. While itis contemplated that the proces of the invention is in generalsufiicient to produce finished gasoline from cracked vapors in one stepit may be at times necessary to subject the condensed gasoline to a mildneutralizing action which is easily accomplished by injecting minoramounts of caustic soda into the rundown line to storage.

The vapors treated may receive suflicient fractionation during thetreatment depending upon the type and capacity of treating toweremployed or they maybe subsequently fractionated in separate equipment,with return of intermediate refiuxes to the primary cracking stage forfurther conversion.

The sludges produced by the process of the invention will also vary incharacter depending upon the numerous factors entering into thetreatment and the steps necessary for their recovery for further usewill necessarily be modified accordingly. In most instances the generalprocedure commonly employed in recovering sludge from liquid phasesulfuric acid treatments is applicable, the sludge being diluted to aproper point with water to cause separation of oily material, and theaqueous solution being concentrated and receiving further-addition ofchemicals to restore it to the proper composition for use. It iscontemplated to continuously regenerate used treating solutions as astep in the treating process.

Numerous examples of operation and the results obtainable therefrommight be given but a few will sufiice to indicate the feasibility of theoperation from a commercial standpoint. As one example oi operation, thegasoline range boiling vapors from a cracking process'operating upon theMid-Continent residuum may be passed under pressure of approximately 50pounds per square inch counterflow to a descending solution containingapproximately 45% of sulfuric acid, 35% of benzene sulfonic acid and 20%of water. The temperature at the vapor exit at the top of the tower maybe held at approximately 345 F. and the vapors further passed in adownwardly direction through a stationary filter bed consisting of amixture of finely divided fullers earth and lime. The finalfractionation of the treated vapors may produce a gasoline suitable inall respects for commercial use. The following tabulation of comparativeproperties of a raw gasoline produced without vapor phase treatment andthat produced by the refining operation just described will show theeffect of the treatment:

Raw gasollne Treated gasoline The continuous regeneration of treatingsolution from the sludge produced in the preceding example, and thecirculation of reagent through the tower to enable its efiicientutilization may make possible the treatment to the point shown in thetabulation by using as low as five pounds of reagent solution per barrelof gasoline, which is well within the required economy since thesulfonic acid is substantially unaffected in the treating andregenerating steps and the only constituent needing replenishment is thesulfuric acid.

As another example illustrative of the operation of the process asimilar operation to the one given may be conducted upon the vaporsproduced from cracking a California residuum. The reagent solutionemployed in this case may contain as the diluting or spacing compoundapproximately 30% of the sulfonic acid oi mouonitrophenol. By utilizingthe same general steps already outlined and an amount of reagentamounting to '7 pounds per barrel of finished gasoline improved resultsindicated by the following tabulation may be brought about:

Raw gas- Treated oline gasoline Gravity A. P. I 53v 2 63. 7 Final B. P405 406 Color, Saybolt 12 30 Color after 4 hours exposure Yellow 25Gums, mg./100 cc 465 22 Sulfur 0. 4i 0. 15

examples of simple aromatic mono-ketones may be mentioned, such asaceto-phenone; propiophenone; butyro-phenone; valero-phenone;isovalero-phenone; tert.' butyl-phenyl ketone; caprono-phenone;iso-amyl-phenyl ketone; dl-v' ethyl-aceto-phenone;ethyl-dimethyl-aceto-phenone; hexyl-phenyl ketone;vpropyl-dimethylaceto-phenone; triethyl-aceto-phenone; lauroylbenzol andpalmityl-benzol.

In addition to the simple mono-ketones may be mentioned the various morecomplex ketones such as the various keto derivatives and the ketonealdehydes and ketone carboxylic acids.

I claim as my invention:

1. In the refining of light hydrocarbon distillates oi the character ofgasoline, the step which comprises treating the distillate in vaporphase with a solution containing suflicient sulphuric acid to effectsubstantial refining of the vapors and to which has been added ahydrocarbon spacing agent in amount suflicient to dilute the sulphuricacid substantially, said agent being selected from the group consistingof the aromatic aldehydes and ketones.

2. A process for refining light hydrocarbon distillates of the characterof gasoline which comprises treating the same in vapor phase withsulphuric acid to which has been added a hydrocarbon spacing agentselected from the group consisting of the aromatic aldehydes andketones.

3. A process for refining light hydrocarbon distillates of the characterof gasoline which comprises treating the same in vapor phase withsulphuric acid to which has been added an aromatic aldehyde as a spacingagent.

4. A process for refining light hydrocarbon distillates oi. thecharacter of gasoline which comprises treating the same in vapor phasewith sulphuric acid to which has been added an aromatic ketone as aspacing agent.

JACQUE c. Momma.

